Core i7-8700K Review: Coffee Lake Brews A Great Gaming CPU

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randomizer

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Unfortunately my current card is a GTX 970, so XP is out of the question. I'm happily running 8.1 though :)
 
That's the Big Kahuna.

I waited-out 270 (AsRock ITX) for my Kaby buy -- now, both my CPU & mobo are effectively orphaned. Some folks seem willing to accept this as 'business as usual' but I think it's craptastic ... especially if Next-Lake is a rinse/repeat of Kaby/Coffee 270/370.

AMD is not 100% innocent but over time has generally exhibited some semblance of backward/forward compatibility.


 

InvalidError

Titan
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It has always been this way and if you somehow thought it was going to be any different this time around, then you were hopelessly naive. 370/390 will die with Cannon Lake next year and you'll need a new motherboard for Ice Lake in 2019.

Unless your livelihood critically depends on always having the latest and greatest everything, there is a simple solution when you disagree with how a company conducts business: skip a few extra generations between upgrades. Switching to AMD may also be an option.

I only upgrade every 4+ years and only buy on the 2nd generation or later of a new architecture so even if platforms lasted two extra years, I'd still need a new motherboard with my next CPU anyway.
 

samer.forums

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People with low budget who bought i3 or Pentium and were planing to upgrade when they have the money.

and now they have to buy another board and there is no way they buy 4 cores i7 after the 6 core at the same price was released.
 

Actually, I'm under the impression that Cannon Lake might only be for lower-power laptop chips, not for desktop parts. Considering Z390 isn't expected until the latter half of next year, it's possible that it might launch with Ice Lake, and if that were the case, compatibility with Z370 could potentially exist.

It would be nice if Intel announced a rough roadmap for planned motherboard compatibility like AMD did. Of course, CPUs usually tend to be a less common upgrade than something like video cards, RAM, or storage, and relatively few people will likely feel the need to upgrade from Coffee Lake to something new for at least a few years, by which point even AMD may be moving on to new motherboards.
 

InvalidError

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In that case, I point you to Broadwell which was intended as a mobile-first architecture and effectively orphaned LGA1150 as a Haswell-only socket. I wouldn't be surprised if there was a repeat of that with Coffee Lake/300-series if Cannon Lake isn't intended for desktop.

By the time Ice Lake launches, LGA1151 will be four generations old, PCIe 4.0, USB 3.2, Thunderbolt as an open standard, etc. will be over a year old. DDR5 will be just around the corner, ultra-fast NVMe storage will be more mainstream, Optane memory/cache/whatever may be one step closer to making sense, etc. All of this means Intel will be long overdue for a DMI and socket update to accommodate the massive increase in IO bandwidth requirements and possibly give mainstream CPUs 4-8 extra on-CPU HSIO lanes for PCIe 4.0/USB 3.2/TB to bypass the DMI bottleneck for primary accessories. I'd be really surprised if Intel was still on LGA1151 in 2019.
 

samer.forums

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DMI should disappear altogether. I hope that by the time we have DDR5 and PCIe 4.0 the chipset will be integrated inside the CPU .
 

InvalidError

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Discrete chipsets aren't going anywhere. We have a separate chip for secondary IOs because chipsets can be made on older generation processes to save die space and pin count on the CPU, simplify signal integrity through the CPU socket and make it possible for mainstream motherboards to still be made using four layers PCBs.
 

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The same way they moved the memory controller into the CPU , they will one day move the chipset there as well.

AMD Epyc CPU has the chipset integrated already , Actually I was hoping for the threadripper to be the same but AMD decided not to do. Atoms have their full SOC as well , all ARM chips as well. in time the Desktop will follow. it will save space on the motherboard and reduce cost as well.
 

InvalidError

Titan
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How much external IO (PCIe, SATA, USB, display, etc.) do Atoms and ARM chips have? Only a fraction of what desktop CPUs have and on mobile/embedded chips, there is extra pressure on integration to save board space. Integrating the memory controller was an absolute necessity because accessing memory over the chipset was a major performance bottleneck and running the FSB fast enough to keep up with memory speed is also horribly power-inefficient.

Integrating the chipset into the CPU for desktop PCs wouldn't save any board space since the boards are made to fit standard form factors. Adding ~80sqmm to the CPU die size would also reduce the wafer yield by ~40%, considerably increasing CPU manufacturing cost, an inefficient use of an expensive fabrication process. If you want to reduce board size, you have to give up standard form factors and space for PCIe slots and other IOs, at which point you are in SoC territory and may as well go with an Atom.

EPYC gets around the lack of chipset by re-purposing PCIe lanes in a similar way to how Intel's chipsets have HSIO lanes that can be configured as either PCIe, USB3 or SATA by the motherboard manufacturer. Every IO on EPYC comes out of its PCIe budget. I'm a little surprised AMD didn't choose to do the same with ThreadRipper, guess it didn't feel like 64 HSIO lanes was enough to make that compromise yet.

 
With the 8700K selling out on launch day, do you think the low amount of stock had anything to do with requiring Z370? I just don't believe the whole power draw thing when a Z170/270 can support an unlocked i7 drawing over 120W.
 

samer.forums

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1- how much I/O in Atom ?

here is an example : Intel Atom® Processor C3850 (12 cores)

https://ark.intel.com/products/97932/Intel-Atom-Processor-C3850-12M-Cache-up-to-2_40-GHz

First : Lanes

PCIe lanes : 16 (rings any bells ? )

PCI Express Revision 3
PCI Express Configurations : x2,x4,x8
Max of PCI Express Lanes : 16

Second : I/O ports

USB 3 Ports : 8
SATA 6.0 Gb/s Ports : 16
Integrated LAN : 2x10/2.5/1 GbE

+ 2x1 GbE (in some other models)

I am 100% Sure intel can do the same for their desktop chips with ease.

2- integrating chipset inside the CPU will save space . for example the itx motmerboards could have 4 Dimm slots instead of 2 maximizing the memory . and will open a place for integrated SAS chips in that place even using Micro ATX motherboard and without the need to go EATX , or add 10GB lan chips , Thunderbolt chip ,or any other chips. or even an NVME M2 slot in that place.

3- ARM ? check the server Grade ARM chips not the mobile ones .. and you will be surprised at the huge i/o ports they offer today.

4- Epyc ? had the threadripper been the same we would have seen an itx ThreadRipper motherboard with ease. as for manufacturere decides which i/o to choose , it is the same anyways .. they always choose which port to use and which to ignore and how many lanes to use from the chip set remember that intel chipset has 24 PCIe lanes that also can be used , the big difference here is that they are bottlenecked by the DMI unlike when they come directly from the CPU itself. ... how it works internally inside the chipset or the CPU does not matter at all , what matters is eliminating that chipset space and eliminating the DMI bottleneck ..

5- Eliminating the Northbridge (memory controllers) allowed us to have the itx form factor .. and eliminating the southe bridge (chipset) will allow us to make itx motherboards have ATX grade components , being 4 Dimms slots , or adding more chips like 10GLan or more nvme or beter sound chip in the chipset place.
 

InvalidError

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Wrong...
https://www.intel.ca/content/www/ca/en/design/products-and-solutions/processors-and-chipsets/denverton/atom-processor-c3000-series.html

The C-series server SoCs have 20 HSIO lanes split between PCIe, SATA and USB3 just like the 100/200-series chipsets. If you use 16 HSIO lanes for the GPU's PCIe, then you have 4 HSIO lanes left for everything else.
 

samer.forums

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Why is the i7 7800X OC @4.9 Ghz not included in the tables ? or even 4.8Ghz OC ? it is very easy to reach 4.8Ghz oc on this CPU using AIO cooling , and you did not care to include it in the test.
 

samer.forums

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First , not all the C3000 are the same , had you looked into different CPUs you would have seen that. (the same not all X CPU have 44 lanes ) .

second : whats your point exactly? this CPU is only 8- 24 watts and you should understand that this is a low voltage CPU ... the power is the barrier here, not that it cant be done on 91 watts CPU , increase the power and you can have as much HSIO as you want.
 

tamalero

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Why every intel fanboys everywhere (specially places like reddit)
Keep mentioning the "delidding" ? Delidding is not a thing for normal gamers, users, etc..
Its used for the most stepped up enthusiasts. Usually right below the guys who use LN2 and custom loops in terms of hardcore users.
 
people do realize it takes about 2 years for intel and amd to "brew" a cpu right? im sure amd had coffee lake 8700k engineering samples in house long before they even released ryzen. both knew winter was coming.

also not sure where people have been but intel has always did two generations on a single motherboard socket... sandy/ivy, haswell/devils, sky/kaby. also you should not be upgrading so often anyways. its pretty much agreed upon that you need 2 generations before an upgrade. those with sky/kaby should at the very least wait a generation or two.
 

samer.forums

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Well intel has a 1000 cores sample some where , but this does not mean they were going to release it if AMD did not threaten them.

it is not about what they can do , it is about when to release it.
 

InvalidError

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The C-series SoC platform only comes with 20 HSIO lanes, which is the same total as Intel's desktop CPUs: 16 PCIe lanes + 4 DMI lanes.


The problem is DIE AREA, not power.

Manufacturing chips on 14nm is expensive. If a 140sqmm die costs $60 to make and you increase the die area to 200-220sqmm by integrating the chipset, you increased the per-die cost to over $90 (the larger area means at least that much lower potential yield per wafer, a proportionally higher chance of each die having a fatal defect and each defect representing a larger hit on the already lowered potential yield) for non-essential IO that could be manufactured for much cheaper on 22nm instead. If Intel integrated the chipset and maintained the same percentile profit margins on its chips, i5 would go up ~$100 while motherboards would be only $30 cheaper from no longer carrying a chipset, less if fanning out those extra IOs away from the CPU socket requires extra motherboard layers.

Integrating non-performance-critical IO into the CPU does not make economic sense in cost-sensitive applications like mainstream PCs.
 

samer.forums

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actually it is both. Power and Area . the power part because you were focusing on the Atoms while our conversation was about the Desktop CPU.

More lanes need more power .

now lets move to Area , Area for what exactly ? 20 more I/O lanes ? so what ? thats not a big deal . you are exaggerating it.

as for needed or not ? ofc it is needed . first cancelling the DMI all together , and second moving to smaller factors and freeing space.

and you are wrong about your $90 difference ... the 6 cores CPU with 16 lanes is the same price of the 28 lanes 6 cores CPU. thats 12 more lanes more than enough for I/O triple the DMI today. there is no $90 die difference sorry.

your theory is right in concept but you exaggerate the price difference . you dont know how much it will cost intel more nor know how much increase in area it needs. you are just ASSUMING.

Intel Core i7-7800X Processor
List Price: $389.00

Intel Core i7 8700K

List price

$359.00 - $370.00

where is your 90 dollar difference ? keep in mind this not only has 12 more lanes enough for I/O , it also has Quad channel controller.

Leave the Pricing for intel to care about, and stop assuming you know the pricing by guessing.
 

AgentLozen

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I like how he apologized. Very gentleman-like.

Wasn't the PCIe controller integrated into the CPU for a while before they (Intel) removed it due to the thermal problems it caused?

Also I suspect InvalidError is speaking hypothetically about die costs. It's not really clear though. If he literally means that it costs $60 to churn out a 140mm^2 die, I'd like to see a source for that. Otherwise he's right, 100mm^2 -> 150mm^2 is a 50% increase in die space and cost if it scales linearly.

Additionally, why Intel prices their chips the way they do is anyone's guess. There are some basic marketing rules they have to follow and there are also expectations from previous generations that they have to meet. A comparison between SkyLake-X and Coffee Lake may not be apples to apples. I'm not trying to say that anyone is "wrong", but there may be more variables to pricing than we anticipate. Why does Nike sell a pair of shoes for $80 when they only cost $4 to make?
 

InvalidError

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IO circuitry doesn't shrink much with process because a large chunk of the die area is taken by IO drivers, termination circuitry, delay lines, analog amplifiers, etc.

As for the pricing between the i7-7700k and i9-7800X, you do realize that you are comparing the absolute top-of-the-line on the 140sqmm die (highest margin) against the bottom of the barrel (lowest margin) on MCC which are an outlet for dies with dead HSIO lanes, cache blocks or dies, clock frequency handicap, power consumption handicap and other non-fatal issues, right? The profit margin that Intel is "losing" by selling 7800X which barely makes sense to most people buying into x299 (even more so now that Coffee Lake provides the same or better performance on a much more affordable platform) is more than accounted for by the much larger profit margins it gets from the remainder of the lineup.
 
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